Department of Public Works

2019 Recommended Street Tree Species List

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Introduction

The San Francisco Urban Forestry Council periodically reviews and updates this list of trees in collaboration with public and non-profit urban forestry stakeholders, including San Francisco Public Works, Bureau of Urban Forestry and Friends of the Urban Forest. The 2019 Street Tree List was approved by the Urban Forestry Council on October 22, 2019.

This list is intended to be used for the public realm of streets and associated spaces and plazas that are generally under the jurisdiction of the Public Works. While the focus is on the streetscape, e.g., tree wells in the public sidewalks, the list makes accommodations for these other areas in the public realm, e.g., “Street Parks.” While this list recommends species that are known to do well in many locations in San Francisco, no tree is perfect for every potential tree planting location. This list should be used as a guideline for choosing which street tree to plant but should not be used without the help of an arborist or other tree professional. All street trees must be approved by Public Works before planting.

Sections 1 and 2 of the list are focused on trees appropriate for sidewalk tree wells, and Section 3 is intended as a list of trees that have limited use cases and/or are being considered as street trees. Finally, new this year, Section 4, is intended to be a list of local native tree and arborescent shrub species that would be appropriate for those sites in the public realm that have more space than the sidewalk planting wells, for example, stairways, “Street Parks,” plazas, and sidewalk gardens, where more concrete has been extracted. The local native species on List 4 provide optimum habitat for local wildlife. The application form to plant a street tree can be found at http://sfpublicworks.org/plant-street-tree.

Biodiversity, Habitat and Climate Change

The City of San Francisco, like other cities around the world, has been accelerating its actions and goal-setting in relation to the interlinked crises of climate change and biodiversity loss. Both the IPCC and the IPBES released significant reports in 2019 on the state of the global climate and biodiversity crises, respectively. Climate change and biodiversity have figured prominently in Urban Forestry Council conversations in 2019, during which many people have advocated for planting local native trees and shrubs to support local pollinators and other wildlife, in order to stem the tide toward an impending global insect apocalypse. Street trees can play a role in climate mitigation and adaptation and in providing habitat for local wildlife. The 2019 approved tree list is part of the City’s larger climate action strategy and can contribute to creating a truly biodiverse San Francisco.

Opportunities for Greening and Supporting Wildlife in the City

In addition to street trees, the City provides many other programs and opportunities for supporting biodiversity and climate resilience in the urban environment. The Department of Public Works manages the Street Parks Program and the Sidewalk Landscaping Permit. Both of these programs hold great potential to install local native plants for wildlife and climate resilience. The San Francisco Plant Finder is a City website that provides recommended plant lists for bringing wildlife habitat into the urban environment. Consult sfenvironment.org/biodiversity as a portal to much more information about the city’s ecology and natural heritage.

For San Franciscans who have the opportunity – whether a front or backyard or other significant space - and are keenly interested in planting a tree for local wildlife habitat, the City strongly recommends planting coast live oak trees, California buckeyes and other local native species, taking care to use seeds or plants that are produced from local San Francisco stock. Consult the City’s bee-friendly nurseries page for sources of local native plants.

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Section 1: Tree species, varieties, and cultivars that do well in most sidewalk locations in San Francisco.

Size Evergreen/ Species Common name Notes Deciduous Small Evergreen Callistemon citrinus lemon bottlebrush Grows low; wide canopy and needs a wide Less than sidewalk; sticky flowers; pollinators. 20’ tall at Magnolia grandiflora ‘Little Gem’ Little Gem magnolia Proven success. maturity Deciduous Crataegus phaenopyrum Washington hawthorn Subject to pests; has thorns; may be susceptible to fire blight; pollinators. Medium Evergreen Agonis flexuosa peppermint willow Standard green-leaf species only. ‘After Dark’ 20-35’ tall variety NOT recommended. Fast grower – at more than 12” annually, requires extensive maturity maintenance when young. Brahea edulis Guadalupe palm Palm tree. Slow growing in San Francisco. Callistemon viminalis weeping bottlebrush Has sticky flowers; pollinators. Magnolia grandiflora ‘St. Mary,’ southern magnolia Melaleuca quinquenervia broad-leaf paperbark Grows fast, dense, irregular form; prefers wind protection; sensitive to cold. Olea europaea fruitless olive Needs a very large basin; prefers wind protection; Swan Hill and Wilsoni preferred; Cal-IPC Limited* Tristaniopsis laurina tristania; water gum Standard species only. ‘Elegant’ variety NOT recommended. Formerly known as Tristania laurina; slow grower – less than 6” annually; pollinators. Large Evergreen Lagunaria patersonii primrose tree Grows well in windy areas; pollinators. More than Lophostemon confertus Brisbane box Formerly Tristania conferta; fast grower. 35’ tall at Magnolia grandiflora ‘Sam Sommers,’ southern magnolia Proven success. maturity ‘Majestic Beauty,’ ‘D.D. Blanchard’ Podocarpus gracilior/Afrocarpus falcatus fern pine Slow rooter. Quercus suber cork oak Needs a large basin and wide sidewalk. Deciduous Platanus x acerifolia ‘Columbia’ London plane; sycamore Prefers wind protection; susceptible to anthracnose and powdery mildew; observation needed.

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Section 2: Tree species, varieties, and cultivars that do well with certain special considerations as noted; may not be appropriate for planting broadly throughout San Francisco.

Size Evergreen/ Species Common Name Notes Deciduous Small Evergreen California lilac tree CA Native cultivar. Not good for narrow Less than Ceanothus ‘Ray Hartman’ sidewalks; pollinators. 20’ tall at maturity Cordyline australis cabbage tree Needs very large basin; do not plant near natural areas; Cal-IPC Limited* Laurus nobilis ‘Saratoga’ Saratoga bay laurel Uneven performer; prefers heat; needs some wind protection; susceptible to pests. Magnolia champaca/M. x alba champak Formerly Michelia champaca; needs wind protection; wide sidewalk; gets powdery mildew and very slow grower. Pyrus kawakamii evergreen pear Plant only in warmest areas of city. Semi- evergreen; leaf spot/fungus likely to occur and may cause premature leaf drop; does not flower well in our climate; susceptible to fire blight. Deciduous Crataegus x lavallei Lavalle hawthorn Appears to be less susceptible to fire blight and other pests compared to other Crataegus; pollinators. Medium Evergreen Arbutus x ‘Marina’ strawberry tree Fruit drop can range from low volume to 20-35’ tall significant. May be short lived; may need to at be replanted in 20-25 years; pollinators. maturity Cassia leptophylla gold medallion tree Semi-evergreen; requires extensive early maintenance. Eriobotrya deflexa bronze loquat Needs wind protection; does not perform well in sandy soils; susceptible to fire blight; pollinators. Magnolia doltsopa sweet michelia Formerly Michelia doltsopa; uneven performer; grafted trees grows very slowly; prefers heat; needs wind protection. Melaleuca linariifolia flax-leaf paperbark Does well in SF.

4 Phoenix dactylifera ‘Medjool’ or ‘Zahidi’ date palm Needs a large basin and wide sidewalk. Syagrus romanzoffiana queen palm Needs heat and wind protection. Trachycarpus fortunei, standard & Chinese windmill palm Does well in many SF climates. ‘Wagnerianus’ Deciduous Jacaranda mimosifolia jacaranda Uneven performer; prefers heat, wind protection, and good drainage; spring leaf drop. Koelreuteria bipinnata Chinese flame tree Structural failure concerns. Pistacia chinensis ‘Keith Davey’ or Chinese pistache Prefers heat and wind protection. standard Large Evergreen Corymbia ficifolia red flowering gum Needs a very large basin and wide sidewalk; More than drops large seed pods; pollinators. 35’ tall at Corymbia maculata/Eucalyptus m. spotted gum Experimental, should do well in climate; lots maturity of mature trees doing well now. Hymenosporum flavum sweetshade Uneven performer; prefers heat, wind protection, and good drainage; pollinators. Lyonothamnus floribundus asplenifolius Catalina ironwood CA Native. Prefers heat and wind protection; prone to transplant shock; very susceptible to phytophthora. Metrosideros excelsa New Zealand Christmas tree Needs a very large basin and very wide sidewalks; pollinators. Pittosporum undulatum Victorian box Self-sows! Do not plant near natural areas or other open spaces; caution, in decline, requires further study; Cal-IPC Watch* Quillaja saponaria Chilean soapbark Availability improving; thrives everywhere; pollinators. Washingtonia robusta Mexican fan palm Prefers some warmth; Cal-IPC Moderate* Deciduous Ginkgo biloba ’ ‘Princeton Sentry,’ ginkgo; maidenhair Slow grower; prefers wind protection. ‘Saratoga’ Ulmus parvifolia ‘Drake,’ Chinese elm Fast grower; requires extensive pruning and maintenance.

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Section 3: Tree species, varieties, and cultivars with limited use cases and potential site restrictions as noted.

Size Evergreen/ Species Common Name Notes Deciduous Small - Evergreen Butia odorata southern jelly palm Does well in many SF climates. Less than Ceanothus ‘Cliff Schmidt’; Ceanothus California lilac tree CA Native cultivar. Additional cultivar and 20’ tall at arboreus standard species (currently only planting ‘Ray maturity Hartman’). Elaeocarpus decipiens Japanese blueberry Slow growing; keep out of strong/prevailing wind; flowers but may not produce fruit at maturity. Eucalyptus conferruminata/E. lehmanni bushy yate Wide canopy; large space needed; pollinators. Heteromeles arbutifolia Toyon, Christmas berry SF Native. Local native, train early for tree form; great for sidewalk landscaping. Prunus lyonii Catalina cherry CA Native. Fruit drop may get messy. Deciduous Acer circinatum Vine maple CA Native

Prunus subhirtella ‘Autumnalis’ Higan cherry Tolerates mild winters better than other flowering cherry species.

Medium Evergreen Agonis flexuosa ‘Burgundy’ Burgundy peppermint willow Better form and structure than other dark- 20-35’ tall leaf cultivars; fast grower. at Archontophoenix cunninghamiana king palm Needs wind protection and summer water. maturity Banksia integrifolia coast banksia Requires extensive early maintenance. Brahea clara Sonoran blue palm Does well in many SF climates. Brachychiton populneus bottle tree Prefers heat and wind protection; needs a large basin due to thick trunk. Cedrela fissilis Brazilian cedarwood Good results so far and needs more time; do not plant under powerlines. Ceiba speciosa silk floss tree Prefers heat, wind protection, large basins. Howea forsteriana Kentia palm Does well in many SF climates. Melaleuca ericifolia swamp paperbark Not often planted, but most look good. Melaleuca squamophloia scaly paperbark Not often planted but should do well. Melaleuca styphelioides prickly-leaf paperbark Can root poorly; prickly leaves. 6 Parajubaea sunkha Sunkha palm Does well in many SF climates. Metrosideros collina ‘Springfire’ 'ohi'a lehua Pittosporum rhombifolium/ Queensland pittosporum Use in warmer parts of the city. Auranticarpa rhombifolia Quercus engelmannii Engelmann oak CA Native (extreme south) Quercus hypoleucoides Silverleaf oak Native to Sonoran desert biome. Quercus rugosa Netleaf oak Native to Mexico. Deciduous Acer buergerianum trident maple Prefers heat, wind protection, and needs summer water. Aesculus hippocastanum horse chestnut Not clear if successful in SF yet; needs summer water. Aesculus x carnea red horse chestnut Gets windburn easily in summer even in protected sites; early deciduous; climate concerns; needs summer water; pollinators. Celtis sinensis Chinese hackberry Prefers heat and needs wind protection; uneven performer; gets pests. Corylus colurna Turkish hazel Not clear if successful in SF yet. Koelreuteria elegans ssp. formosana Chinese flame tree Semi-deciduous. Large Evergreen Angophora costata Sydney red gum More Brachychiton acerifolius flame tree Semi-deciduous. than 35’ tall at maturity Corymbia citriodora Lemon-scented gum Eucalyptus nicholii willow-leaf peppermint Experimental; should do well in SF climate. Eucalyptus polyanthemos silver dollar gum Needs a large basin; fast grower; high maintenance; drops limbs; pollinators. Geijera parviflora Australian willow Prefers heat, and needs wind protection; pollinators. Parajubaea torallyi Bolivian mountain coconut palm Does well in many SF climates. Quercus agrifolia coast live oak SF Native. Requires large sidewalk/basin (and wind protection?); likely unsuitable for most street tree locations. Quercus ilex holly oak Needs wind protection; sidewalk space; gets powdery mildew. Quercus tomentella island oak CA Native. Availability improving. Quercus virginiana southern live oak Continue to test; doing well so far.

7 Quercus wislizeni Interior live oak Bay Area Native Deciduous Acer rubrum ‘Armstrong’ columnar red maple Prefers heat; requires summer water. Liriodendron tulipifera tulip tree Uneven performer; susceptible to aphids followed by sooty mold; requires summer water. Platanus racemosa ‘Roberts’ California sycamore (Roberts) CA Native. Large basin and wide sidewalk; (central and southern) Quercus coccinea scarlet oak Experimental. Quercus frainetto ‘Forest Green’ Italian oak Availability improving; more testing needed. Quercus phellos willow oak More performance testing needed; requires summer water. Tilia tomentosa silver linden Performance testing needed. Ulmus parvifolia x carpinifolia ‘Frontier’ frontier elm More performance testing needed. Ulmus propinqua ‘Emerald Sunshine’ emerald sunshine elm More performance testing needed. Ulmus wilsoniana ‘Prospector’ prospector elm More performance testing needed. Ulmus japonica x wilsoniana ‘Accolade’ accolade elm More performance testing needed.

8 Section 4: Local Natives - these are tree and arborescent shrub species that are appropriate for the larger public realm, including stairways, plazas and “Street Parks,” as well as sidewalk gardens in wider sidewalks with large cut-outs. Local native trees and shrubs are optimum for providing wildlife habitat throughout the city. Evergreen/ Species Common Name Notes Deciduous Evergreen Ceanothus thyrsiflorus California lilac Grows quickly in the right conditions. Garrya elliptica Silk tassel Lyrical, hanging flowers. Heteromeles arbutifolia Toyon Beautiful red berries in late fall. Myrica (Morella) californica California wax myrtle Beautiful as a hedge or specimen tree; needs a moist site. Prunus ilicifolia Holly-leafed cherry Spectacular indigenous occurrence at the top of Bayview Hill. Rhamnus (Frangula) californica California coffeeberry Widely planted for attractive evergreen leaves. Quercus agrifolia Coast live oak Landmark tree at 23rd and Castro. Quercus chyrsolepis Canyon live oak Unusual indigenous occurrence at Lake Merced. Deciduous Aesculus californica California buckeye Landmark tree at 22nd and Pennsylvania and other locations. Sambucus cerulea Blue elderberry Landmark tree near Folsom Street at Bernal Heights Boulevard.

Palms – Quick Reference All palms described here can also be found in one of the three lists above. Small Section 3 Butia odorata southern jelly palm Does well in many SF climates. Medium Section 1 Brahea edulis Guadalupe palm Needs a large basin. Section 2 Phoenix dactylifera ‘Medjool’ or ‘Zahidi’ date palm Needs a large basin and wide sidewalk. Section 2 Syagrus romanzoffiana queen palm Needs heat, wind protection. Section 3 Archontophoenix cunninghamiana king palm Needs wind protection and water. Section 3 Brahea clara Mexican blue palm Does well in many SF climates. Section 3 Howea forsteriana Kentia palm Does well in many SF climates. Section 3 Parajubaea sunkha Sunkha palm Does well in many SF climates. Section 2 Trachycarpus fortunei, standard & Chinese windmill palm Does well in many SF climates. ‘Wagnerianus’ Large Section 2 Washingtonia robusta Mexican fan palm Prefers some warmth; Cal-IPC Moderate* Section 3 Parajubaea torallyi Bolivian mountain coconut palm NEW: does well in many SF climates; big

9 Selected Resources

Bee-Friendly Nurseries https://sfenvironment.org/plant-nurseries-bee-friendly

California Native Plant Society, Yerba Buena Chapter http://cnps-yerbabuena.org/

California Native Plant Society, Calscape https://calscape.org/

City Trees https://sfenvironment.org/city-trees

Friends of the Urban Forest https://www.fuf.net/

Green Connections https://sfplanning.org/project/green-connections?page=3002 iNaturalist https://www.inaturalist.org/home

Local Plant Nurseries http://sfplantfinder.org/resources.html#plant-nurseries

Park Forestry Improvement Program https://sfrecpark.org/park-improvements/2008-clean-safe-bond/park-forestry-program/

Protect the Pollinators https://sfenvironment.org/pollinators

Recreation and Open Space Element http://openspace.sfplanning.org/

Right Tree, Right Place https://www.pge.com/righttreerightplace/

10 San Francisco Plant Finder http://sfplantfinder.org/

San Francisco Trees http://www.sftrees.com/

Sidewalk Landscaping http://sfpublicworks.org/services/permits/sidewalk-landscaping

Street Parks Program http://sfpublicworks.org/streetparks

Street Trees and Plants http://www.sfpublicworks.org/trees

StreetTreeSF https://sfpublicworks.org/streettreesf

Urban Forest Master Plan https://sfplanning.org/urban-forest-plan?page=3166

Urban Forestry Council https://sfenvironment.org/about/taskforce/urban-forestry-council

Urban Forest Ecosystems Institute https://ufei.calpoly.edu/

Acknowledgements California Native Plant Society Flora Grubb Gardens Friends of the Urban Forest Mike Sullivan, author of Trees of San Francisco San Francisco Recreation and Parks San Francisco Public Works, Bureau of Urban Forestry San Francisco Environment

Information on this list in the notes column for species that attract pollinators is from the Urban Forest Ecosystems Institute website. Links for California native trees and arborescent shrubs point to that species on the Calscape website. 11